In telecommunication networks, one of the critical parts is a connecting unit between the two end points of sub-sections of the networks, for example from an outdoor distribution node to the entrance of an office building or multi-dwelling residence. To connect such end points, optical fiber cables are often being used as connecting units. To ensure functionality and reliability of the networks, those optical fiber cables have to protect transmission media (e.g. optical fibers) inside of the optical fiber cables from stresses and the surrounding environment.
Those optical fiber cables are often placed in outside plant environments, and also at the intersection of outside plant and inside plant environments. In such environments, protecting transmission media from water is especially important. If water penetration at such connecting units and/or optical fiber cables is allowed, it may create various problems. First, longitudinal water penetration along the unit into premises and/or equipment locations could cause damage to components located close to each end of the unit. Second, if water is allowed to migrate alongside or remain in contact with a unit, it may diffuse towards the transmission media. If water is allowed to come into contact with the glass transmission media, then it may have a detrimental effect upon lifetime and/or transmission performance of the transmission media. The detail of how the presence of water on the surface of the glass cause mechanical degradation and reduce lifetime is shown in publications such as T. A. Michalske and S. W. Freiman, “A Molecular Mechanism for Stress Corrosion in Vitreous Silica”, J. Am. Ceram. Soc. 66 [4] 284-288 (1983).
To protect transmission media from water, optical fiber cables tend to be covered with extra layers of protection around the transmission media. However, because network duct areas are limited in most of the applications, there is a constant incentive to reduce the overall diameter of individual units and cable components, including optical fiber cables.
Accordingly, it is desirable to overcome the problems presented above.